In Japan, kitsunetsuki was noted as a disease as early as the Heian period and remained a common diagnosis for mental illness until the early 20th century.[3][4] Possession was the explanation for the abnormal behavior displayed by the afflicted individuals. In the late 19th century, Dr. Shunichi Shimamura noted that physical diseases that caused fever were often considered kitsunetsuki.[5] The belief has lost favor, but stories of fox possession still occur, such as allegations that members of the Aum Shinrikyo cult had been possessed.[6]